Guitar Neck Repair

[Pete L]

I need some advice please. I know nothing about guitars or string instruments. A piano or keyboard would be a different proposition and I would try anything.

I have been given a broken guitar. I offered to try to repair it and if I can I would like to return it, although I was told that I could keep it. The top of the neck where the tightening pegs go has broken off. My instinct is that I can glue this with my favourite two pack epoxy however, the design has an inherent weakness and I am not sure that glue alone will be adequate. Therefore I my try to use dowels of some kind. Again there is little material to even do this. I could try to make a metal plate to cover the whole back, complete with cut out frets. What pressure or stress do the strings get to when tightened to tune?

Alternately, should I try to graft on a new neck piece end (or even a whole neck) and make it solid and change the peg types. Where can I buy alternative type peg tighteners for a solid flat neck end. I see on E Bay that gold plated plates and screws are available. Are these for stiffening necks.

Photo 1 shows the broken neck. Photo 2 is the top peg section which is detached.
Photo 3 shows some pins in the side of the fret. They are only on this side. If I try to remove the whole fret do I have to remove these pins first? Is the fret groved on the inner back and held by these pins?

Apologies if some of the terminology is incorrect. Your help would be appreciated.

Peter

[kamusur]

Peter

When strung up dependent on scale length and tuning, average tension for a nylon string (guitar in the photo) might be aroung 40-45 kilos (say around 85 to 90 pounds) while a steel string would typically be double that (also dependent on tuning and scale length etc)

There would be many ways to fix this as well (as others will chime in im sure) fwiw this is my 2 cents worth.
It looks like most of the timber headstock is still with us so I would use it. Glue it back on (i would personally use hide glue) maybe using Titebond bond original which is also a water soluble glue would perhaps be a better choice (than 2 pack epoxy or any waterproof glue), easier to clean up and repeat the glue up if things don't go to plan.
Remove the tuning machines from the broken headstock before you start (reuse them later if they still work) and find yourself a suitable way to hold the mess together say a jig, a vice or some tape to steady the work whilst it sets.
I wouldnt turn it into a solid headstock as it was always designed to be slotted. When finished you could sand the stock down and even reinforce with a headplate (back and front) veneer, make it a feature and it will also cover the repair and any missing wood splinters.It will add even more strength to the damaged area. There should be no need for dowels.

Steve

[DarwinStrings]

the design has an inherent weakness and I am not sure that glue alone will be adequate

The design is only inherently weak if you drop the thing a bit like a glass, it is fine if you drink out of it but drop it on the concrete and it is not likely to work any more.

I agree with Steve, no need for epoxy (though you could use it) or dowels. The most important part is how you re-clamp it. Try to look for clamping methods (on the net) that are used to glue headstock scarf joints together and that will give you a idea of how to set it up to clamp it. Do dry clamp runs and remember that once you apply glue things get a bit more slippery so you need stops or a jig that will keep it aligned while you clamp.

Jim

[Pete L]

Thanks for the replies. What you are both saying is that glue should be adequate for a repair and stand up to the string tension. Given the reduced wood joining surfaces because of the cut out design I am surprised. I have already had three or four dry runs at clamping and that is no problem.

By inherent weakness I meant for re-gluing, not the original unbroken design. I rather like the shape and I have only seen this feature on one old expensive guitar. I don't believe that this is a particularly good one. So veneer front and back - or even a metal plate and veneer on the back is what I will try. I do use animal glue however, if I use the epoxy I can also fill any missing bits in the bottom holes and clean out more accurately, so that the pins will refit and turn properly.

There are six strings. Two or three remains are in place. Do I take it to a music shop to restring or, what gauge of nylon strings should it have if I buy on line?

Peter

[auscab]

I like to clamp them like this, shape the blocks first ,and then glue them on to the sanded finish so it sticks well ,with 5 minute 2 pack epoxy .

Then glue the break with what ever you like , I would be using a 24 hour 2 pack epoxy, plenty of working time.
Any glue joint done well should be stronger than the wood around it, gappy glue ups is why they fail again , 2 pack can save you there though . Added extras like dowels can weaken the joint.depending on how your doing it.
You have to keep a close look out for hair line secondary fractures either side of the break too
When dry chisel off the blocks and shave back to the finish .Then fill and refinish.
cheers Rob.

PS, you can glue the blocks on with one piece of newspaper between the block and the finish ,when you go to take it off it will snap of at the paper ,if your lucky.

[Pete L]

I finally decided that I had to do this repair and drop other projects. Thanks to the advice received the method was easy. Simply glue and veneer both top and bottom for strength.

The main body is I think mahogany and I had a suitable offcut. I wanted a veneer of this for the underside, yet thicker than furniture veneer. So I glued both ends to a piece of timber and ran it through the thicknesser until it was a little over 2mm thick. I then simply cut out the centre section that I wanted. I did the same for a top side veneer. The fretboard looks like walnut or similar. I did not have any so settled for blackwood.

I had removed the pegs and was ready for the glueing. I decided against the epoxy and settled for Tightbond. I left it overnight and then glued on the two veneers, both done during the following day. Day three I trimmed and shaped the veneers and cleaned up. All that was left was to walnut stain the top veneer and polish. At first I used shellac however I decided that it may not stand up to useage - hardly a logical decision because I have no idea how to play the thing! So I sanded off, re-stained and used a polyurethane satin finish.

One of my objectives was to try to blend the finish into the original used appearance. I think that I have achieved that. Steel wool was used to blend the joins together. I then cleaned up the whole guitar and polished it with a non silicon finish. The fret was cleaned with steel wool and an oil and rubbed clean.

I went to a local shop for strings and I could have bought them for $10 and done it myself. I let them do the stringing so that they could tune it. I was not sure if I could tune it from a piano?

An additional cost was Book 1, Guitar Method by Gary Turner and Brenton White. I have yet to try it.

Photos attached. Thanks again for the help.
Peter

[petersemple]

Look slike a nice repair to me. Well done. Enjoy learning.

[kamusur]

Good work Pete. As an aside,, that long ago when I bought their fingerstyle book it was available with a cassette!

Steve